1. Field of the Invention
The present invention relates to a lighting apparatus in which the light generated from a light source including a light-emitting diode (hereinafter called LED) mounted on a light source rod is radiated onto an object through a light guide plate, or in particular to a lighting apparatus for a liquid crystal display unit.
2. Description of the Related Art
Liquid crystal display units are used for many products. Due to the lack of a light emitting ability, however, a liquid crystal display unit requires a front lighting apparatus for radiating light from the front side or a back lighting apparatus for radiating light from a non-display surface on the reverse side of the display screen.
In the case where the liquid crystal display unit is used for a comparatively large object such as the display screen of the personal computer, a front lighting apparatus or a back lighting apparatus comprising a cold cathode ray tube is used as a light source, wherein the light emitted from the cold cathode ray tube is projected toward the display surface or the reverse non-display surface of the liquid crystal display unit through a light guide plate.
The cold cathode ray tube, however, is too bulky to be used for illuminating the liquid crystal display unit used with a small product such as a portable telephone. In such a case, a front lighting apparatus or a back lighting apparatus comprising a light source configured with an LED coupled with a light source rod is used. The light emitted from the light source rod is projected toward the display surface or the reverse non-display surface of the liquid crystal display unit through a light guide plate.
FIG. 2 schematically shows a conventional lighting apparatus comprising a light source coupled to a light source rod, wherein the light source including the LED 40 coupled to a light source rod is formed in isolation from the light guide plate. The problem, therefore, is that a considerable time is consumed for assembly work.
In view of the problem described above, the object of the present invention is to provide an easy to produce lighting apparatus using a light source formed by coupling an LED to a light source rod.
According to this invention, there is provided a lighting apparatus for causing the light from a light source to enter the incident surface of a light guide plate and to project the light toward an object of the illumination from the exit surface of the light guide plate extending in the direction perpendicular to the incident surface toward an object of illumination, wherein the light source is made by placing a light-emitting diode, on or near a light source rod extending in the longitudinal direction parallel to the incident surface of the light guide plate, and the light source rod is integrally made by forming a slot in a common plate.
The present invention may be more fully understood from the description of preferred embodiments of the invention set forth below, together with the accompanying drawings.